Studies on the molecular mechanism of genetic recombination will be continued using Escherichia coli as a model system. One aspect of the research will be focused on the structure and function of the recombination enzyme, recBC-DNase. We have recently isolated two subunit proteins from the enzyme and succeeded in reconstituting the intact enzyme molecules from the subunits. Biochemical characterization of each subunit will be studied in more detail especially in relation to the biological function of the intact enzyme. Another major research project will be an attempt to develop an in vitro recombination system. The recently E.coli specialized transformation system would be used as a tool to detect and assay recombinant molecules produced in vitro.